An ink jet recording apparatus requires a drive system for performing a recording sheet feeding/discharging operation and a recording head maintaining operation, in addition to carriage travelling operation. Conventionally, printers have a switching mechanism that enables a single drive motor to perform these sheet feeding/discharging and recording head maintaining operations in order to miniaturize and reduce the price of the apparatus.
The switching mechanism switches a drive force of a sheet forward motor between a pump drive system and a sheet feed/discharge drive system when the carriage has moved from a home position to a printing region and when the carriage has moved from the printing region to the home position. This switching feature involves selectively meshing a switching gear with gears of the sheet feed/discharge system and with gears of the pump system such a switching feature is generally thought to be acceptable, however, it is not without shortcomings. In particular, the gears cannot be meshed with each other smoothly because they are not phased together. As a result, sheet feed timings may be disturbed. Furthermore, conventional apparatuses require a disadvantageously large number of components.
Further, an ink jet recording apparatus includes a cleaning mechanism be disposed in a region outside a data recording region to maintain a recording head in a satisfactory condition at all times. As a result, the width of the apparatus is necessarily increased. The increased width is especially disadvantageous in an ink jet recording apparatus dedicated to color printing. For example, same apparatuses use yellow, magenta, cyan, and black inks and further use two kinds of inks, dark and light, for each of these colors. Consequently, the recording head that jets these inks in the form of ink droplets is necessarily increased. Also, capping unit and the cleaning mechanism whose size depends on the size of the recording head are necessarily large-sized. As a result, if the carriage, the recording head, the capping unit, and the cleaning mechanism are disposed within the housing at a high density in an effort to miniaturize the recording apparatus, the printing margins disadvantageously are reduced. For example, the cleaning mechanism may inadvertently move into the carriage travelling path such that during the recording operation, the cleaning mechanism contacts the carriage, thereby disturbing the recording operation.
Further, the number of nozzle openings of the black recording head for jetting black ink and of the color recording head for jetting three kinds of color inks is increased in order to accommodate the needs for high-density and high-speed printing. In association therewith, if the sizes of the recording heads in the sheet forward direction and in the sheet width direction are increased, the sizes of the caps for sealing the respective recording heads are necessarily increased. As a result, the sealability of the caps is impaired due to displacements or the like at the time the caps come into contact with the recording heads.